For example, newspapers are printed by a web offset printing press. The newspaper web offset printing press is configured by a plurality of feeder devices, a plurality of printing units, a turn bar device, and a folding unit. Therefore, when webs are fed to the printing units from the respective feeder devices, printing is performed on the webs. Then, after traveling routes of the plurality of webs are changed by the turn bar device, the webs are overlapped on one another in a predetermined order. Thereafter, the webs are folded lengthwise by the folding unit, cut widthwise to have a predetermined length, folded widthwise to form a folded quire, and then discharged as a newspaper.
A printing unit in such a newspaper web offset printing press requires a printing plate for printing articles or advertisements, and printing is performed with the printing plate being wound around a plate cylinder. Thus, in order to replace an article or advertisement with another, it is necessary to stop the printing unit and replace the printing plate with another. Thus, there is a problem such as lowering of the productivity of newspaper printing, and occurrence of waste paper.
In view of this, in a rotary press having an added printing device described in Patent Literature 1 below, for example, a paper feeding unit, a printing unit, and a folding unit are provided, and an ink-jet printing mechanism is also provided in the printing unit. In an ink-jet printing device described in Patent Literature 2 below, a group of ink-jet heads is provided so as to face a printing paper transported by rolls in the anterior and posterior positions.